This invention relates to a fluorescent display device, and more particularly to a fluorescent display device including a graphic display section and a segment display section.
Conventionally, a fluorescent display device is known in which a segment display section including luminous segments arranged in a predetermined pattern and a graphic display section adapted to carry out a desired character or figure display by means of a plurality of luminous dots are constructed integral with each other. In the so-constructed fluorescent display device, the segment display section and graphic display section are merely arranged in a single envelope, wherein a drive system and an electrode structure for the segment display section are constructed in a manner different from those for the graphic display section.
More particularly, the segment display section, as disclosed in, for example, Japanese Patent Application Laid-Open Publication No. 111986/1975, is conventionally constructed according to a so-called intermediate mounting system wherein mesh grids are fixed on an anode substrate within an envelope. The so-constructed segment display section is driven according to a dynamic drive system wherein the mesh grids are scanned in turn to supply a display signal synchronized with the scanning to segment anodes.
On the contrary, the graphic display section arranged in the same envelope, as disclosed in, for example, Japanese Patent Application Laid-Open Publication No. 231482/1988, is generally constructed in such a manner that a plurality of linear grids are arranged in parallel with one another above an anode substrate and both ends of the grids are interposedly held and adhesively fixed with respect to the sealing portion of the envelope. The so-constructed graphic display section is driven according to a dual wire grid drive system wherein each adjacent two linear grids are scanned one by one in turn and anodes each are supplied with a display signal synchronized with the scanning.
In the conventional fluorescent display device, as described above, the segment display section and graphic display section are constructed different in electrode structure and drive system from each other. This renders the manufacturing of the fluorescent display device highly complicated and troublesome, to thereby cause the respective display sections to require drive circuits separate from each other.
Also, in the conventional fluorescent display device, the two display sections employing different electrode structures and drive systems are arranged in the same envelope, resulting in a wiring pattern provided on the anode substrate being complicated and the width of the pattern being decreased. This renders the use of an ITO film exhibiting large resistance impossible and, as a result, the conventional fluorescent display device is compelled to substitute an Al wiring of small resistance therefor. Therefore, particularly in a front emission type fluorescent display device (FLVFD), it is required to form an anti-reflection film on an anode substrate to prevent light reflected on the Al wiring from adversely affecting a display site and then form the Al wire on the anti-reflection film, resulting in manufacturing of the display device being further complicated.